UNE Biochemistry Midterm Study Bank
Succinate is a substrate for which complex in the electron transport chain?
a.) Complex 1 (NADH-1 oxidoreductase)
b.) Complex IV (Cyt c oxidase)
c.) Complex V (ATP synthase)
d.) complex II (Succinate-Q reductase)
Complex II (succinate-Q reductase) (D)
Which of the following would be consistent with an exergonic reaction?
a.) ∆S would be negative
b.) ∆G would be negative
c.) ∆S would be positive
d.)∆G would be positive
∆G would be negative (B)
Which of the following describes the malate-aspartate shuttle system?
a.) Carries NADH from the cytoplasm directly into the mitochondria
b.) Generates 2.5 molecules of ATP in mitochondria per each NADH from
glycolysis
c.) Moves NADH from the mitochondria to the cytoplasm
d.) Relies on malate dehydrogenase in the inner mitochondrial membrane
e.) Requires reduction of pyruvate to lactate for oxidizing NADH
Generates 2.5 molecules of ATP in mitochondria per each NADH from glycolysis (B)
ATP is a high energy molecule that is often hydrolyzed during reactions. The
energy within ATP is stored primarily in which of the following components of the
molecule?
a.) In the high energy phosphate bonds
b.) In the adenine base
c.) In the D-ribose group
In the high energy phosphate bonds (A)
,Dinitrophenol is an uncoupler of the electron transport chain. The addition of
dinitrophenol will have which of the following impacts?
a.) Decrease the pH of the intermembrane space
b.) Increase oxygen consumption
c.) Decrease oxidation of NADH
d.) Increase ATP production
Increase oxygen consumption (B)
In the malate aspartate shuttle, glutamate is converted to _______ in the
mitochondria while aspartate is converted to _______ in the cytosol.
a.) Oxaloacetate; malate
b.) alpha-ketoglutarate; oxaloacetate
c.) Oxaloacetate; glutamate
d.) Aspartate; alpha-ketoglutarate
e.) Malate; oxaloacetate
alpha-ketoglutarate; oxaloacetate (B)
The glycerophosphate shuttle is a major shuttle of most tissues. Which of the
following best describes the transfer of electrons by this shuttle?
a.) Electrons are directly transferred from glycerol-3-phosphate to NAD
containing glycerol phosphate dehydrogenase
b.) Electrons are directly transferred from glycerol-3-phosphate to an FAD
containing glycerol phosphate dehydrogenase
c.) Electrons are directly transferred from DHAP (dihydroxyacetone phosphate) to
an FAD containing glycerol phosphate dehydrogenase
d.) Electrons are directly transferred from glycerol-3-phosphate and DHAP
Electrons are directly transferred from glycerol-3-phosphate to FAD containing glycerol
phosphate dehydrogenase (B)
Heat can be generated by brown adipose tissue in hibernating mammals. Which
of the following is most likely the mechanism by which this occurs?
a.) Increased ATP production by ATP synthase
b.) Expression of a protein that uncouples the ETC
, c.) An increased pH gradient across the inner mitochondrial membrane
d.) A decrease in oxygen consumption
Expression of a protein that uncouples the ETC (B)
Allosteric activators of hemoglobin will increase binding through what
mechanism?
Binding the protein, and keeping it in the "R" conformation
An enzyme has a mutation within the substate binding site that reduces the
binding of the coenzyme needed for covalent catalysis. What is likely to result as
a consequence of this mutation?
The enzyme will not be able to form the transition state complex
How do most enzymes reduce activation energy needed to move a reaction
forward?
Providing an active site most complimentary to the transition state
Under which energy conditions, AMP will bind to phosphofructokinase 1 (PFK1)
and glycogen phosphorylase at site unique of the active site. This enhances the
activity of these enzymes. This is an example of which of the following types of
enzyme regulation?
a.) Allosteric activation
b.) Allosteric inhibition
c.) Competitive inhibition
d.) Covalent modification
Allosteric activation (A)
Which of the following best describes an enzyme inhibitor that increases the Km,
but does not change the V-max?
a.) Inhibition by covalent modification
b.) A non-competitive inhibitor
c.) An allosteric inhibitor
d.) A competitive inhibitor
A competitive inhibitor (D)
An enzyme is participating in a general acid-base catalysis reaction with an
optimal reaction pH of 6.0. If acid is added to the environment reducing the pH to
3, what is the likely impact to the rate of the reaction?
a.) The rate is likely to decrease as the pH is out of optimal catalytic range.
b.) The rate is likely to increase as the proton concentration has decreased.
Succinate is a substrate for which complex in the electron transport chain?
a.) Complex 1 (NADH-1 oxidoreductase)
b.) Complex IV (Cyt c oxidase)
c.) Complex V (ATP synthase)
d.) complex II (Succinate-Q reductase)
Complex II (succinate-Q reductase) (D)
Which of the following would be consistent with an exergonic reaction?
a.) ∆S would be negative
b.) ∆G would be negative
c.) ∆S would be positive
d.)∆G would be positive
∆G would be negative (B)
Which of the following describes the malate-aspartate shuttle system?
a.) Carries NADH from the cytoplasm directly into the mitochondria
b.) Generates 2.5 molecules of ATP in mitochondria per each NADH from
glycolysis
c.) Moves NADH from the mitochondria to the cytoplasm
d.) Relies on malate dehydrogenase in the inner mitochondrial membrane
e.) Requires reduction of pyruvate to lactate for oxidizing NADH
Generates 2.5 molecules of ATP in mitochondria per each NADH from glycolysis (B)
ATP is a high energy molecule that is often hydrolyzed during reactions. The
energy within ATP is stored primarily in which of the following components of the
molecule?
a.) In the high energy phosphate bonds
b.) In the adenine base
c.) In the D-ribose group
In the high energy phosphate bonds (A)
,Dinitrophenol is an uncoupler of the electron transport chain. The addition of
dinitrophenol will have which of the following impacts?
a.) Decrease the pH of the intermembrane space
b.) Increase oxygen consumption
c.) Decrease oxidation of NADH
d.) Increase ATP production
Increase oxygen consumption (B)
In the malate aspartate shuttle, glutamate is converted to _______ in the
mitochondria while aspartate is converted to _______ in the cytosol.
a.) Oxaloacetate; malate
b.) alpha-ketoglutarate; oxaloacetate
c.) Oxaloacetate; glutamate
d.) Aspartate; alpha-ketoglutarate
e.) Malate; oxaloacetate
alpha-ketoglutarate; oxaloacetate (B)
The glycerophosphate shuttle is a major shuttle of most tissues. Which of the
following best describes the transfer of electrons by this shuttle?
a.) Electrons are directly transferred from glycerol-3-phosphate to NAD
containing glycerol phosphate dehydrogenase
b.) Electrons are directly transferred from glycerol-3-phosphate to an FAD
containing glycerol phosphate dehydrogenase
c.) Electrons are directly transferred from DHAP (dihydroxyacetone phosphate) to
an FAD containing glycerol phosphate dehydrogenase
d.) Electrons are directly transferred from glycerol-3-phosphate and DHAP
Electrons are directly transferred from glycerol-3-phosphate to FAD containing glycerol
phosphate dehydrogenase (B)
Heat can be generated by brown adipose tissue in hibernating mammals. Which
of the following is most likely the mechanism by which this occurs?
a.) Increased ATP production by ATP synthase
b.) Expression of a protein that uncouples the ETC
, c.) An increased pH gradient across the inner mitochondrial membrane
d.) A decrease in oxygen consumption
Expression of a protein that uncouples the ETC (B)
Allosteric activators of hemoglobin will increase binding through what
mechanism?
Binding the protein, and keeping it in the "R" conformation
An enzyme has a mutation within the substate binding site that reduces the
binding of the coenzyme needed for covalent catalysis. What is likely to result as
a consequence of this mutation?
The enzyme will not be able to form the transition state complex
How do most enzymes reduce activation energy needed to move a reaction
forward?
Providing an active site most complimentary to the transition state
Under which energy conditions, AMP will bind to phosphofructokinase 1 (PFK1)
and glycogen phosphorylase at site unique of the active site. This enhances the
activity of these enzymes. This is an example of which of the following types of
enzyme regulation?
a.) Allosteric activation
b.) Allosteric inhibition
c.) Competitive inhibition
d.) Covalent modification
Allosteric activation (A)
Which of the following best describes an enzyme inhibitor that increases the Km,
but does not change the V-max?
a.) Inhibition by covalent modification
b.) A non-competitive inhibitor
c.) An allosteric inhibitor
d.) A competitive inhibitor
A competitive inhibitor (D)
An enzyme is participating in a general acid-base catalysis reaction with an
optimal reaction pH of 6.0. If acid is added to the environment reducing the pH to
3, what is the likely impact to the rate of the reaction?
a.) The rate is likely to decrease as the pH is out of optimal catalytic range.
b.) The rate is likely to increase as the proton concentration has decreased.
